DOI

10.5703/1288284314267

Abstract

Cracking of bridge decks poses a significant threat to the lifespan of our nation’s bridges. Cracking has been shown to occur in various climates and geographical areas and can be seen on various types of superstructures. Often these cracks appear before or shortly after opening the bridge to live loads. Cracks in the deck create a path for water and deicing salts to reach the steel, often leading to corrosion of the reinforcement, greatly reducing the durability of the deck. Measures must be taken during design and construction to control bridge deck cracking and prolong the lifespan of bridges. In addition, there is a need to develop effective methods to repair cracks in existing bridge decks. This project consisted of four phases of research to investigate methods to control and repair deck cracking. The first phase of the study was a field investigation of a new bridge that is experiencing significant deck cracking. The second phase was an evaluation of previous recommendations regarding curing and concrete mix design and their effect on the control of deck cracking. The third phase of the study evaluated the effectiveness of a variety of commercially available crack repair products. The fourth phase evaluated the influence of the design and layout of the deck reinforcement in controlling crack widths. Based on the findings of this study, inadequate deck reinforcement and poor construction practices, particularly deck casting during poor weather conditions, were identified as major causes of bridge deck cracking for the structure investigated. Recommendations are provided for the design and construction of new bridge decks as well as for the repair of existing bridge decks. In particular, a minimum 7 day minimum wet cure is recommended along with alterations to the concrete mix to reduce bridge deck cracking through the reduction of concrete shrinkage. Recommendations are also provided regarding the amount of reinforcement required to optimally control crack widths and improve the durability of bridge decks. Finally, guidance is provided regarding both the selection and application of deck repair materials.